X-ray contrast composition



Patented Jan. 5. 1943 X-RAY CONTRAST COMPOSITION William Bell, kly and Jules R. Gilbert, New York, N. Y.

No Drawing. Application March 2, 1940, Serial No. 321,914

2 Claims. (Cl. 16795) The present invention relates to diagnostic and therapeutic preparations and it particularly relates to improved preparations for use in cholecystographic examinations or in gall bladder radiography.

It has been found that certain alkali metal salts of tetraiodophenolphthalein are most useful in connection with cholecystographic examinations or gall bladder radiography, but considerable difiiculty has been experienced in obtaining preparations which will remain stable over along period of time in solution form and will give satisfactory shadows of the gall bladder.

It has been found that these tetraiodophenolphthalein preparations, particularly in the form of the mono-sodium salts, are not stable in water insoluble or emulsion form even with stabilizing agents, such as' gelatin, acacia, tragacanth and so forth.

It is important that the tetraiodophenolphthalein compound, when ingested, be fully disintegrated and absorbed in the digestive tract without being converted into sticky and insoluble masses or without being passed through the stomach or digestive tract in unchanged condition.

It has not been found satisfactory to prepare preparations of these tetraiodophenolphthalein metal salts dispersed in insoluble form with protective colloids or organic acids, although in some instances these may be included. It has been found most satisfactory to prepare true solutions of tetraiodophenolphthalein rather than colloidal dispersions thereof, with a slight or excess alkalinity.

In preparing a preferred compound according to the present invention, it has been found most satisfactory to use the tetraiodophenolphthalein di-sodium salt dissolved in a relatively large amount of water in the presence of an alkali, preferably caustic alkali, such as caustic soda, together with the addition of small amounts of essential oils and saccharin.

Although protective colloids, such as gelatin, may be added or organic acids, such as citric acid, may be included, generally it is preferred to omit these materials.

The resultant product which is prepared, should be a true solution as contrasted to a colloidal suspension, should have an excess of alkalinity and should be devoid of free acid.

To give one preferred formula for making up the composition of the present application, the following materials may be used:

The flavoring, such as the oil of lemon or saccharin, may be omitted.

In making up the above preparation, it has been found most satisfactory to heat the 1600 cc. of water to about 40 and then add the sodium compound with agitation.

Then the caustic soda is added to alkalinize the mixture. The mixture is then stirred and heated to C. and is permitted to stand overnight.

If flavoring is desired, the oil of lemon and saccharin may be added at this point or they may be replaced by other suitable flavoring materials.

Finally the mixture is made up to 2200 cc. by addition of water and then is filtered.

It is found that the resultant preparation when utilized is devoid of colloidally suspended material, will be most satisfactorily absorbed to give the proper shadow or cholecystographic effects and will be devoid of sediment and stable over long periods of time. The pH should vary between 7.5 to 10 and preferably between 8 and 9, and although casein, gelatin or agar-agar may be added, desirably these materials are omitted.

This method of preparation is much preferable to one in which gelatin and di-sodium tetraiodophenolphthalein are added to water heated to 400, followed by the addition of caustic and citric acid, with or without the addition of coloring matter, oil of lemon and saccharin.

Where citric acid is added, it may preferably be added in the form of the tri-sodium citrate so that it will remain in this condition and most desirably no acid is added to convert either the tetraiodophenolphthalein to the mono-sodium salt or to decrease the amount of sodium in the tri-sodium citrate.

It has been found that by preparing the solu- -tion of tetraiodophenolphthalein in the above manner, the solution is buffered and such buflering action may be enhanced by the addition of salts of strong alkalies and weak acids to give a pH of about 8.

Among the salts which may be used are sodium phosphate, particularly dior tri-sodium phosphate, sodium borate or sodium carbonate.

The present procedure may also be utilized in the preparation of stable solutions of the disodium salt of tetraiodophenolphthalein in ampule form for intravenous injection, in lieu of making fresh solutions just prior to injection. Where used for intravenous injection the solution is devoid of flavoring materials.

The di-sodium salt of tetralodophenolphthalsin is most readily commercialized as a powder which is used to prepare a fresh solution for oil or intravenous administration, the concentration depending upon the dosage and varying from 2 to 7 grams per dose in a suitable amount of water.

The substantially alkaline solution of di-sodium salt of tetraiodophenolphthalein is much superior to the substantially neutral solution 0! the di-sodium salt of tetraiodophenolphthalein or the dispersion of the mono-sodium salt of tetraiodophenolphthalein in that the solution 0! the present invention is definitely stable, whereas the last-mentioned solutions will sediment upon standing and result in unsalable products.

As many changes could be made in the features and details, and many apparently widely dlflerent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A stable shadow producing composition for cholecystographic purposes consisting of di-sodium tetraiodophenolphthalein dissolved in a caustic soda solution having a pH of about 8 2. A process of producing a stable sodium tetraiodophenolphthalein solution, which comprises alkalinizing a solution of the di-alkali metal salt of tetraiodophenolphthalein with caustic soda to a pH 01' about 8 to 9.

WILLIAM BELL. JULES R. GILBERT. 

